BPSC TRE 1 PYQ Quiz – Higher Secondary Teacher Exam Subject Zoology

Explanation: Corona radiata is a layer of follicular cells surrounding the ovum, not sperm. Sertoli cells provide nutrition to developing sperm, and Leydig cells produce testosterone.

Explanation: A test tube baby is conceived via in vitro fertilization (IVF), where fertilization occurs outside the body in a laboratory dish, and the embryo is then implanted into the uterus.

Explanation: Drosophila salivary gland chromosomes are polytene chromosomes, which are large and easily visible due to repeated DNA replication without cell division.

Explanation: A 9:7 ratio in F2​ is characteristic of complementary gene interaction (epistasis), where two genes interact such that the recessive homozygous condition of either gene masks the expression of the other.

Explanation: If only daughters inherit the disease from an affected father and normal mother, it indicates X-linked dominant inheritance, as the father passes his X chromosome to all daughters.

Explanation: DNA replication involves multiple enzymes including DNA ligase (joins fragments) and DNA polymerase I (fills gaps and proofreads). Ribonuclease is involved in RNA degradation, not DNA replication.

Explanation: Metacentric chromosomes have a centromere located at or near the middle, giving two equal arms.

Explanation: Charles Darwin published his theory in On the Origin of Species by Means of Natural Selection in 1859.

Explanation: Mendel chose pea plants because they exhibited clear, contrasting traits (e.g., tall vs. short, yellow vs. green seeds) and could be easily cross-pollinated.

Explanation: Darwin’s theory of natural selection is a well-supported explanation for evolution. The listed aspects are not considered “wrong” but are core components of his theory.

Explanation: In both prokaryotes and eukaryotes, the start codon AUG codes for methionine, which initiates protein synthesis.

Explanation: Each secondary oocyte yields one ovum (plus one polar body), so 100 secondary oocytes → 100 ova. Each secondary spermatocyte yields two spermatids, so 100 secondary spermatocytes → 200 sperms.

Explanation: Crossing-over occurs between non-sister chromatids of homologous chromosomes during the pachytene stage of prophase I in meiosis.

Explanation: Bartholin glands (greater vestibular glands) are located on either side of the vaginal opening and secrete mucus to lubricate the vagina.

Explanation: A 1:2:1 ratio in both genotype and phenotype occurs in cases of incomplete dominance (e.g., flower color in snapdragons) or codominance (e.g., ABO blood group).

Explanation: Helicase unwinds and separates the two DNA strands by breaking hydrogen bonds. DNA polymerase adds nucleotides; gyrase relieves supercoiling.

Explanation: In cytoplasmic (maternal) inheritance, organelles like mitochondria and chloroplasts are inherited via the cytoplasm of the egg, not the sperm.

Explanation: XX males and XY females can occur due to translocation of the SRY gene from the Y to the X chromosome during meiosis.

Explanation: In Mendel’s experiments, each trait (e.g., seed color, seed shape) is controlled by separate genes. No single gene controls two different traits.

Explanation: Restriction enzymes (endonucleases) cut DNA at specific recognition sites, essential for recombinant DNA technology.

Explanation: Eli Lilly and Company, in collaboration with Genentech, commercially produced human insulin using recombinant DNA technology in 1983.

Explanation: Human insulin was the first hormone produced using genetic engineering (recombinant DNA technology) and approved for medical use in 1982.

Explanation: Statements B and C are false. Drones are male, develop from unfertilized eggs (haploid), while workers develop from fertilized eggs (diploid).

Explanation: In DNA fingerprinting, the child inherits half of their DNA from each parent, so their band pattern is a combination of both parents’ patterns.

Explanation: An immunogen is a substance that can provoke an immune response (antigenicity + immunogenicity). All immunogens are antigens, but some antigens (haptens) are not immunogens alone.

Explanation: Polyculture refers to the simultaneous cultivation of multiple fish species in the same pond, often to utilize different ecological niches.

Explanation: Governments implement conservation projects (e.g., Project Tiger, wildlife sanctuaries) to protect endangered species and habitats.

Explanation: Harmful effects depend on pollutant concentration, exposure duration, and the susceptibility of the organism.

Explanation: The acrosome contains enzymes (hyaluronidase, acrosin) that help the sperm penetrate the egg’s outer layers during fertilization.

Explanation: Endangered species can be preserved through cloning (somatic cell nuclear transfer), gene banks (cryopreservation of gametes/embryos), and maintaining genetic diversity in gene pools.

Explanation: Carolus Linnaeus is known as the father of modern taxonomy for developing the binomial nomenclature system.

Explanation: Vikramshila Gangetic Dolphin Sanctuary is located in Bihar, India, on the Ganges River.

Explanation: The dermis of the skin is composed of dense irregular connective tissue, providing strength and elasticity.

Explanation: Epstein-Barr, Varicella-Zoster, and Herpes simplex are all DNA viruses (Herpesviridae family), not RNA viruses.

Explanation: The internal carotid artery supplies oxygenated blood to the brain in rabbits and other mammals.

Explanation: Uranyl acetate and lead citrate are commonly used as heavy metal stains to enhance contrast in TEM.

Explanation: In the unit membrane model (Davson-Danielli model), each dense band is about 25 Å thick, with a total membrane thickness of ~75 Å.

Explanation: Facilitated diffusion requires carrier proteins (permeases) and is stereospecific, unlike simple diffusion which is non-specific and does not require carriers.

Explanation: A typical Golgi stack consists of 3 to 8 cisternae in most animal and plant cells.

Explanation: The sarcoplasmic reticulum is a specialized smooth ER in muscle cells that stores and releases calcium ions for contraction

Explanation: Echinodermata (e.g., starfish, sea urchins) are exclusively marine. Porifera and Mollusca have freshwater and terrestrial representatives.

Explanation: Choline dehydrogenase is located on the outer surface of the inner mitochondrial membrane (cristae), involved in electron transport.

Explanation: Amyloplasts are a type of leucoplast that store starch, commonly found in roots and tubers.

Explanation: Phagosomes are vesicles formed around ingested particles, which fuse with lysosomes to become phagolysosomes (secondary lysosomes). Granules and residual bodies are types of secondary lysosomes.

Explanation: During G1​ phase, the cell grows and synthesizes RNA and proteins in preparation for DNA synthesis in the S phase.

Explanation: Synapsis (pairing of homologous chromosomes) occurs during the zygotene stage of prophase I in meiosis.

Explanation: Haemoglobin is a simple protein (conjugated with heme), but among the options, it is the best example. Thyroglobulin and caeruloplasmin are glycoproteins.

Explanation: Kupffer cells are specialized macrophages in the liver that phagocytose old and damaged red blood cells.

Explanation: An actin filament is composed of two helical strands of globular (G) actin monomers twisted together to form fibrous (F) actin. Tropomyosin and troponin are regulatory proteins associated with actin.

Explanation: Cushing’s syndrome results from prolonged high levels of cortisol, often due to adrenal tumors or excessive ACTH.

Explanation: The capture-recapture method (Lincoln-Petersen index) is used for mobile animals, while quadrat method is for sessile plants.

Explanation: Deserts are characterized by extreme temperatures, very low rainfall, and sparse vegetation.

Explanation: FSH stimulates Sertoli cells in seminiferous tubules to support spermatogenesis. LH acts on Leydig cells to produce testosterone.

Explanation: Neutral α-glucosidase is a marker enzyme secreted by the epididymis, important for sperm maturation

Explanation: Fertilization typically occurs in the ampulla, the widest part of the fallopian tube.

Explanation: The mesovarium is a fold of peritoneum that suspends the ovary from the posterior body wall.

Explanation: Gonadal steroids (testosterone in males, estrogen in females) drive the development of secondary sexual characteristics during puberty.

Explanation: Type B spermatogonia undergo mitotic divisions to produce primary spermatocytes, which then enter meiosis.

Explanation: The cortical reaction is triggered by sperm-egg fusion, preventing polyspermy by hardening the zona pellucida.

Explanation: By the end of the 24th week, the fetus occupies the entire uterine cavity.

Explanation: Oxytocin stimulates uterine contractions, and relaxin helps relax pelvic ligaments and soften the cervix during childbirth.

Explanation: Louise Brown, born in the UK in 1978, was the first successful IVF baby.

Explanation: Common male contraceptives include condoms (barrier) and vasectomy (surgical sterilization).

Explanation: Syphilis was the first well-documented STD outbreak in Europe in the late 15th century, known as the “Great Pox.”

Explanation: In a dihybrid cross, independent assortment gives a phenotypic ratio of 9:3:3:1 in the F2 generation.

Explanation: In incomplete dominance, heterozygotes show an intermediate phenotype because neither allele is completely dominant.

Explanation: Sutton and Boveri independently proposed the chromosome theory of inheritance, linking Mendel’s laws to chromosome behavior.

Explanation: Metacentric chromosomes have centromeres in the middle, forming a V shape during anaphase as sister chromatids are pulled apart.

Explanation: Quantitative real-time PCR (qRT-PCR) measures DNA amplification in real time, allowing quantification of starting template.

Explanation: The primary application is cloning specific genes for research, medicine, and industry.

Explanation: Dolly the sheep (1996) was the first mammal cloned from an adult somatic cell using nuclear transfer.

Explanation: MMBL introduced the first three Bt cotton hybrids in India: MECH 12, MECH 162, and MECH 184.

Explanation: Sir Alec Jeffreys developed DNA fingerprinting (DNA profiling) in 1984.

Explanation: In layer feed, yellow maize has the highest percentage, followed by polished rice, barley, groundnut cake, and corn gluten.

Explanation: Apis dorsata (the giant honey bee) is the largest species among honeybees.

Explanation: Leishmania causes leishmaniasis, a parasitic disease transmitted by sandflies.

Explanation: All listed activities can have unintended environmental impacts: land modification (habitat loss), construction (pollution), DDT (bioaccumulation).

Explanation: The Calvaria tree (Sideroxylon grandiflorum) relied on the dodo for seed dispersal; its decline followed the dodo’s extinction.